Carton blank



FIG. 1 is a top plan view of a carton blank embodying my new design, the bottom being substantially _the same in appearance;

FIG. 2 is a right edge view of the blank shown in _FIG. 1; and

FIG. 3 is a bottom edge view of the blank shown in FIG. 1.

The dash lines represent fold lines and score lines. 

The ornamental design for a carton blank, as shown and described. 